Gear-cutting machine



J y 4, 1944-v I L. o. CA B LSEN 2,352,689v

\ VGEAR'CUTTINGIMAEHINE Filed Oct. 18, 1939 a 13 Sheets-Sheet l I INVENTOR v LEON/7P0 0. CARLSEN g ATTORNEY July 4, 1944. v o. cA RLsEN 2,352,689

GEAR CUTTING MACHINE Filed Oct. 18, 1939 1s sheets-Sheet? INVENTOR LEON/9RD O. C/IKLSEN .ATTORNEY July 4, 1944. L. 0'. CARL'SEN 2,352,689

GEAR CUTTING MACHINE Filled Oct. 18, 1939 15 Sheet-Sheet 3 INVENTOR LEON/IEO 0. CHRL5EN l ATTORNEY July 4, 1944.

GEAR CUTTING MACHINE L. o. cARLsN 2,352,689

Filed .0 m. 18, 1939 13 Sheets-Sheet 4 in, Im ulm INVENTOR LEON/9RD O. CA/QLSEN ATTORNEY July 4, 1944. o. CARLSEN GEAR CUTTING MACHINE 13 Sheets-Sheet 5 Filed Oct. 18, 1939 Inventor LEON/QED 0. CHELSE/V July 4, 1944. L o, CARLSEN 2,352,689

GEAR CUTTING MACHINE Filed Oct. 18, 1939 1s Sheets-Sheet 7 Imvcntot LE/VOHED 0; CARL s/s/v y 9 4- Y L.- 0. CARLSEN I 2,352,689

GEAR CUTTING MACHINE V Filed Oct. 18, 1939 ISSheets-Sheet 9 INVE NTOR LEON/9E0. 0. CHELSEN MATTORNEY I July 4, 1944. 1.. o. CARLSEN GEAR CUTTING MACHINE Filed Oct. 18, 1939 13 Sheets-Sheet 1O ISmaentor LEON/9 RD 0. cease/v.

(Ittomeg y 944- y L. b. CVARLSEN 2,352,689

GEAR CUTTING MACHINE "Filed 001:. 18, 1959 13 Sheets-Sheet 11 INVENTOR LgN/MD 0. CHKLSE/V RiToRNEY y L. o. CARLSEN 2,352,689

GEAR CUTT IIIIIIII NE ssssssssssssssss NNNNNN OR July 4, 1944. L. o. CARL'SE'N I 2,352,689

GEAR CUTTING MACHINE Filed Oct; 18, 1939 13 Sheets-Sheet 13 Juventor (lttornel Patented July 4, 1944 NT OFFICE GEAR-CUTTING MACHINE Leonard 0. Carlsen, Rochester, N. Y., assignor'to V Gleason Works, Rochester, N. Y., a corporation of New York Application October 18, 1939, Serial No. 300,025

' 17 Claims.

The present'invention relates to machines for producing gears and particularlyto machines of the geared-roll intermittent-indexing type for generating tapered gears. .In a more specific aspect, the invention relates to two-tool'machines 'for finish-cuttingstraight bevel gears.

One purpose of the present invention is to provide a two-tool straight'bevel gearv generator for general purpose work whichwi'll be easier to set up and which will be faster and more accurate in operation than any-such generatorsheretofore built.

To this end, one object of the invention is to provide an improved tool-actuating mechanism which will more surely hold theptools-against possible deflection during their cutting strokes. I

A further object of the invention is to provide a-machine of the geared-roll type in'which the various mechanisms for controlling the ma- 1 chine operations are so arranged that they may :rea'dily'be assembled and timed While on'a bench,

therebysimplifying the construction and timing of the machine.

"Another. object of the invention is to provide a machine of-the type described in which the var- .ious mechanisms for controlling the machine op- .highvspeed-iwithou't shock orvibration.

J'Another objectof the invention isito provide in .a-machine .of the character "described, mechanism:for moving 'the work rapidly to and from :loadingposition forremovalof a completed gear .or chucking of a new gear blank.

A further object of the invention is to provide 'for a .machine of the character described, an improved stock-dividing 'gauge which will be simple inconstruction and-universal in range.

lstill'another objectofthe invention is to provid'ea method for anda machine-"capable of cutting straight bevel gears with longitudinally crownedlteethso that-mating gears-may be produced that mesh with localized tooth bearing or contact andthatare capable of adjustment in use. Y

Other objects of the invention will beapparent hereinafter from the specification and fromthe 'recitalof the'app'ended claims.

In the drawings: r Fig. I is '-a :side elevation, with parts broken away,-oi;a machine constructed according-to one embodiment of this invention, .the=work head being shown swung out of operating position;

Fig. 2 is plan view of this machine; I I Fig.3 is anelevational view lookingat one .end

ofthe machine, parts-being broken. away; i

Fig. 4 is..an.-.ele vational,viewlooking at the front .end of the tool, carrying cradle Fig. 5- is a-transverse sectional view through the cradle; --Fig..6.is a fragmentary sectionalview through the cradletakenonthe line 6B of Fig. 5 and .showing theupper tool carrying slide and ram;

. Fig.7 is a detail sectional view on an enlarged scale showing parts mechanism; v

Fig. 8-is a diagrammatic view illustrating the movement of a tool across-the face of agear blank in the cutting of a bevelgear with-crowned teeth accordingto the process-of the presen invention;

Fig. 9 1s afragmentary plan view cf-a bevel gear. so cut;

-Fig.l0 .is a'developedsectional view of the indexing mechanism of the machine;

Fig. 11' isa view looking at one end of the index mechanism; I

Figsl2 is a view taken at right angles to Fig. 11 and looking at.the index mechanism from-one side; 1 c p a Fig. .13 is a fragmentary sectional viewshowing the feed cam and-.-the mechanism connecting I thiscamwith the sliding-base;

Fig; 14- is a; drive diagram of the machine;

Fig. 15 is a-.view looking at theiront-end of the Wo1"l head of the machine and showing particularly a stock dividing device,- constructed according to one embodiment of the present-invention, in use, locatinga roughened bevel gear blank for cutting; r

Fig. 16 is'aplan 'ViEWOf the parts shown in Fig.'15;r

Fig. 17'is1a diagrammatic view illustrating the use of the-stock dividinggaugefor locating a gearof a given pitchhaving an oddnumber of teeth;

Fig.- 18 is a diagrammatic view illustrating the use .of' the same gauge-in locating 'a' gear of much larger pitch but'having also an odd number of teeth; I

Fig. 19 is a diagrammatic view illustrating the use :of a modified "form of'stock dividingdevice in the positioning of'a gear of fine pitch having an 'evennumberof teeth; r

Fig: .20 is axcorrespondin'gyiew, showing the Same stock dividing device .used for positioning a of the ram-reciprocating gear of much coarser pitch but having also an even number of teeth;

Fig. 21 is a section on the line 2l2l of Fig. 15 but on a. much enlarged scale;

Fig. 22 is a diagrammatic view illustrating a stock dividing device made according to a still further modification of this invention in use for positioning a fine pitch gear having an even number of teeth;

Fig. 23 is a corresponding view illustrating the use of the same device for positioning a coarse pitch gear having an odd number of teeth;

Fig. 24 is a developed view of the stock dividin device shown in Figs. 22 and 23 ;-and

Figs. 25 and 26 are fragmentary sectional views on the lines 25-25 and 26-26 of Fig. 24, respectively.

In general the machine illustrated in the drawings is an improvement over the two tool straight bevel gear generator of U. S. Patent 1,656,633 of January 17', :1928'; Like the'machine of that patent it has apair'of planing-tdols-which are reciprocated simultarieously im opposite directions to out alternatelyo'nopposite-sides of a tooth of: a gear blank. -The=tools-"are mounted on an oscillatory'cradlefwhich isdriven intime with the rotation of '-the work spindle to effect the generatingrolhof themachinesf Thetools may cut during roll in one direction only or during lroll in both" directions." For generating a gear, the -blank'is fed intooperativerelation with the-tools, then blank and tools'are rolled together to generate 'atooth of thegeary then the blankis withdrawn fromoperative positionand"indexed. Then the blank is fed back into the tools and'the cycle-begins anewu' When allofthe teeth have been cut, the blank may be wihdrawn' to' loading-position to" permit taking the completed gear off "of the machine and chuckingot a new gear blank 7 7 In the machine illustrated,--each of the-tools cuts on movement in one direction-only and is withdrawn fromcuttingposition on -itsreturn stroke. Each tool-is secured 'to 'a'slide which reciprocates in a ram= that, in turn; is 'mounted in a, tool carrier for reciprocation in a direction perpendicular -to=the direction'o'f-reciprocation of the-slide. The two tool carriers are mounted on the cradle for angular adjustment thereon to determine the paths of movement of the tools. The slides-are actuated by a crank to -impart the cutting and return' movements to the tools and the rams are actuated by a cam to move the tools to and from-cutting'position at'opposite ends of the strokes of the slides.- The crank and cam are mounted upon the same shaft.

The tool reciprocating and relieving. mechanisms' of the present machine are similar to those of my prior Patent No. 2,101,237, but in the'present machine, the cam operates eachramthrough a pivotally mounted lever that carries a roller at one endwhich engages the cam; and a roller at its opposite end which engages the ram. Through the. levers, power is applied to each ram at a point directly in line with the point of cut of. the tool carried .b Ltheslide which is mounted upon .the ram. Hence. each tool is heldsurely against deflection while. it .is cutting- Ordinarily in the cutting of a bevel gear, the tip f the tool travels in a. plane tangent to the root,,-cone of the gear.- It is contemplated empljoyingfcams .on the present machine, however, that will vary the depthat which a tool vcuts as the; tool moves, across theefaceof a. gear blank.

With the, present machine. then, it. is, P0551191; to

move the tip of the tool in a curved path as it crosses the face of the blank with the result that tooth surfaces may be out upon the gear which are longitudinally convex or crowned. A gear cut in this fashion will mesh with its mate with a localized tooth bearing or contact and hence, unlike an ordinary bevel gear, will be insensitive to variations in mountings or loads.

The cradle and the work spindle are driven in timed relation, for generating the tooth profiles of a gear, by a train of gearing which includes change gears governing the rate and ratio of the rolling movement and the number of teeth to be cut in the blank. The several gear trains are arranged in the present machine so that all of the change-gears are located at one end of the machine where they are readily accessible to the operator.

As in the machine of prior Patent No. 1,656,-

633, the work spindle is journaled in a head that is-rnounted on a sliding base which is reciprocable in the-direction of the axis of the-cradle to move the work to and fromoperative position. As in the prior patent mentioned, the movement of the sliding base is controlled-by a rotary feed cam that-has two tracks, one of which is used duringthe rough-cutting of a gear and the other during finish-cutting. The machine of the present invention differs, however, from the machine of --theprior patent in that the feed cam is- 10- cated'at the same-end of the machine as the change gears so that the operator can-readily make 'the change over from rough-cutting to finish-cutting or vice versa without going around the machine. 1 By putting the feed cam at the tool end ofv the machine, moreover, all control parts are kept clear of the cutting coolant and of chips. Further, lubrication of the parts is facilitated. In the present machine, the feed cam is operatively connected with the sliding base by a lever which is secured to. a cylinder that houses a reciprocable piston which is fastened to the sliding base. When the sliding base is in operating position, the piston bottoms in one end of the cylinder and is held in that position by fluidpressure. The motion of the feed cam, then, is transmitted directly from cylinder to piston and thence to the sliding base. To move the sliding base to loading position, pressure fluid is admitted to the cylinder to move the piston in the cylinder and thereby move the slidingbase relative to the feed cam and. lever. By reversing the direction of flow of the pressure fluid the sliding base can be returned again to operative position. A hand valve is provided to control the movement of the piston in the cylinder. This valve is located at the same end of the machine as the change gears.

As in the machine of prior Patent N0. 1,656,633, the work spindle is driven through a differential,

one member of which is locked against rotation 2 during cutting. To. index the work, this member is periodically released and. actuated. In order to. operate the present machine at the higher speeds desired, a new and improved type of index mechanism has been provided for controlling the locking and unlocking of the differential member and the rotation of this member when released. The index mechanism. includes 8. Geneva wheel which is geared to the housing of the differential, a lock-up dog which holds the housing against rotation during cutting of the tooth of the gear blank, an axially 'reciproc'able -cam,'a pin that is ada ted toengage the Geneva iaasasse wheel a wh c s secured t t e cam :a means for moving said car-n periodically axially-so that the cam will' be moved periodicallyinto. operative relation with the locking dog, to trip the locking dog out of locking-position,- .and the pin will be moved periodicallyinto operative relation with the Geneva wheel, to rotate the wheel through an angle sufiicient to effect indexing.

-The Geneva mechanism insures a slow'start and .stop motion for indexing, permitting indexing to be eifected at high speed.

The index mechanism and -.the ieedecam and cooperating parts are mounted in a removable bracket so that they may be assembled on the bench. This makes it easier to time the machine I of the teeth of the blank in the finish cutting operation.

Three difierent embodiments of the'improved stock-dividing mechanism are illustrated in the accompanying drawings. Inoneembodiment, a gauge is provided for dividing stock of gearshaving odd numbers of teeth. 'In another embodiment, a gauge is provided for dividing stock of gears having even.numbers of :teeth. In athird embodiment a gauge is provided which is luniversal in use and which may be employed for dividing stock of gears having eitherodd or even numbers of teeth.

The gauge for-gears with odd'numbers of teeth is in the ,form of a rotatably adjustable member :that has a peripheraltooth-rlike projection whose sides are of straight profile but lie in helices of opposite hands so that they diverge from one another around the periphery of the gauge. The gauge is so ,mountedupon the machine that the median line through the tooth-like projection lies in the-horizontal centerline of the machine.

Hence, whenthe tooth-likeprojection isengaged in a tooth space of a gear having an odd number. of teeth, the median line of that tooth of the gear, which is diametrically opposite the tooth space, will also lie in .thehorizontal .center line ofthe machine and be disposed centrallybetween the two cutting .tools. By .rotatably,

ferentpitch. Thus the same gauge may be used for positioning any gear blank having an odd number of teeth whose pitch is within the cutting range of the machine.

The-gauge for even numbersof teeth is similar to the gauge already described except that it is of female form. Ithas twocooperating toothlike projections whose adjacent side surfacesare helical surfaces of opposite handso that they form a tooth space whose sides diverge from one another aroundthe periphery of the gauge. The projections are adapted to straddle atooth of the gear blank to center thediametricallyopposite tooth of the blank betweenthe two cutting tools. By rotatably adjusting the gauge it may bevused to locate gears of different pitch. e

The universal typegauge has two tooth-like helical projections which at one end merge tod su aq s and the hands of t e :two .p i eti n are oppos t The wo proiectionsmay b enaae d' itherrin a -;tooth space of ,a-rou h d .gearblankior locating agea r blank having an odd numberpf teeth, or they may straddle a tooth of a,gear blank for locating a-blank that has an even number of teeth. The third type gauge may be used, then, to position any gear blank within the cutting range of the machine.

Reference will now behad to the drawings-for a more detailed description of the invention. .30 denotes the base or frame of the machine. .On the baseare mounted the cradle 3 l (Figsh'i and 5), which carries the cutting tools, and the sliding base 32 (Figs. 1 and-2), which 'carries'the work spindle.

The cradle is a full circular cradle and is journaled'bymeans of roller bearings. .and35 on spaced semi-circular ways ,36 and 3'! formed on the base 30 (Fig. 5). It is held in position by the semi-circular capmember-38whichis secured to the base by screws 39 (Figs. i2and 4). The cradle is held against axial movement :in the base andcover plate by a flange or shoulder 40 formed on the base and by the semi-circular retaining plate or gib 4| which is --bolted to the column and'to the capmember :38.

Mounted in the cradle 31 for angularadjustment therein are a pair of angularly adjustable tool carriers and 455(Figs. 4 and-6) The adjustment of each'tool carrier determinesthe path of movement of the cuttingtool mountedithereon. For cutting straight bevel gears, .the tool carriers are adjusted so that the'two tools will move in paths inclined to one another at an angle equal -to theanglebetween opposite sides of .a'tooth-ofthe gear to be out. Adjustment of .each carrier is effected by rotation of a shaft 42 (Fig. 4) that is journaledinthecradle andlthat carries a spur pinion '43 which meshes with a spur gear segment 44 that is secured to-the carrier. The carriers are secured in adjusted positions by a gib 4 9 that 'is-secured to the .cradle by-bolts 59. Suitable graduations areprovided on-the gib and carriers to-permit the adjustments to be made accurately.

Each of these --tool carriers is formed with spaced arcuate guides orbearing surfaces .48 and 41 that are adapted to seat on cylindrical ways formed internally in the cradle. One of "these ways is shown in dotted'lines at 48in Fig. 4. The

. construction isisubstantially the same as shown in gether. Each projection-has divergin O posite -75 myprior-PatentNo. 2,101,237 and need not 'fur- .ther be describedhere.

The carrier .45 carries the upper tool sliderand ram and the carrier =45 carries the-lower tool slide and ram. The two @tool carriers and the parts mounted thereon are identical in construction save for the reversal of parts necessary to the different positions of thetwo tools and accordingly in the following description only the upper carrier will "be described-in detail; Correspondingpa'rts of theother carrierwill be denoted by corresponding reference numerals primed.

Mounted'to reciprocate upon the carrier 45 in a direction parallel to the axis of the cradle l is a ram 50 (Figs. 4, 5 and .5). The rain is mounted stor slide upon laterally spaced-sets of upper and lowerlroller bearings 51 and 52-at-its forward end andvupon upperand lower roller bearings. 53 and 5d at its rear end,and "it is guided in its movement by spaced roller bear.- ings 55 and fifi at its forward end-and 51 and 58 atits rearend. e

" Secured to the front end of the ram 59 by means of screws 69' is" a dove-tailed guide 6i which extends in a direction at right angles to the direction of movement of the ram. The upper tool slide 62 is mounted to reciprocate on the dove-tailed guide BI and the lower tool slide 62 is mounted to reciprocate upon the corresponding dove-tailed'guide fiI' of the lower ram. The upper and lo'wer'tools T and T, respectively, are mounted on the slides 6| and 6!, respectively, for'adjustment in the direction of movement of the. slide and in a direction at right angles thereto according to known practice and in the manner described in my prior Patent No. 2,101,237 above mentioned.

The tool slides are reciprocated by a crank having a radially adjustable pin I9 (Fig. that is connected by means of a link II and pin I2 to an arm I3 which is fastened to the shaft I4. The shaft "I4 is suitably journaled in the cradle 3| and'has an enlarged head I5 (Figs. 4 and 5) at its forward end. A pair of blocks I6 and I6 are pivotally mounted on pins 11 and TI, respectively, in this head. These blocks engage in elongated'slots I8 and I8, respectively, formed in the slides 62' and 92', respectively, so that as the shaft I4 is oscillated by the crank, the slides 62 and 62' are moved simultaneously in opposite directions.

The crank pin I9 is carried by a block 80 which is radially adjustable in a slot formed in the front end of the shaft 82.

The shaft 82 is mounted co-axially' of the cra dle. It is journaled at one end in the cradle on roller bearings 83 and at its opposite end is journaled in the base 39 on roller bearings 84. Adjustment of the radial position of the crank-pin I9 may be effected by rotation of a shaft 85, which is journaled in the shaft 82, and which carries at its forward end a pinion (not shown) that meshes with a rack that is integral with or secured to the block 89. After adjustment the block is clamped in position by a headed clamping member (not shown) that is adapted to en gage the block and which is manipulated by the rod 86. This rod is also mounted in the shaft 82. The means for adjustment of the block 89 and for securing it in any adjusted position form 'no'part of the present invention and for that reason are not further illustrated.

Integral with the shaft 82 is a cam 99 which controls the movements of the rams 59 and 59.

This cam is operatively connected with each ram by a lever 9| (Figs. 5, 6 and '7). Each lever BI is pivotally mounted by means of a pin 92 between upper and lower lugs or ears 93 that are formed integral with the associated tool carrier 45 or 45'. Each lever carries at one end a roller 95 that engages the face of cam 99. At its opposite end, each lever carries a roller 91 that is journaled in the lever on a stud98. The rollers 95 engage the face of the cam 99 at diametrically opposite sides of-the cam. Each roller 91 engages a hardened block 99 that is secured to the rear end of one of the rams 59 or 59'. The lengths of the lever arms 9I and the positions of the rollers 91 are so selected that the rollers 91 are substantially in line, as is clearly shown in Fig 5, with the points of cut of the cutting tools T and T. Thus power is applied to each ram at a point in line with the point of cut to hold the corresponding tool in cutting position.

Each block 99 carried by the ram 59 or 59 is held in engagement with the roller 91 of corresponding lever 9I, and each roller95 carried by the lever is held in engagement with the cam 99 by action of a spring-pressed plunger 94 (Fig. 6). Each plunger is housed in the carrier 45 or 45' and engages a lug 96 that is secured by a screw I99 to the corresponding ram'59 or 59'.

The cam 99 is so formed that when one of the tools T is in cutting position, the other tool T will be withdrawn therefrom.

The crank shaft 82 is driven from the main motor I99 of the machine (Figs. 2 and 14) through a pair of bevel gears IM and I92, the shaft I93, speed change gears I94 and I05 (Figs. 3,2 and 14), shaft I96, bevel gear I01 and bevel gear I98 (Figs. 5 and 14). The latter gear is secured by screws I99 to a flange integral with the crank shaft 82. 1

Through the mechanism described, the fetus 45 and 45 are actuated to move the cutting tools T and T alternately to and from cutting position and the slides 62 and 62 are actuated to produce the alternate cutting and return strokes of the tools.

The cradle is'oscillated to effect the generating and return rolls through a train of gearing which will now'be described. Mounted on the shaft I93 (Figs. 2, 3 and 4) is a spur gear III] that meshes with the spur gear III which is secured to a stub-shaft'l I2 (Fig. 1). The shaft H2 is journaled in the base of the machine and has secured to its upper end a spur gear H3. This gear meshes with the spur gear II4 which is secured to a shaft II6 (Figs. 1, 3 and 14) that is journaled in the base of the machine.

The shaft II B is connectable by means ofa clutch III, that may be of any standard or suitable construction, with an aligned shaft H8. The shaft II8 carries at its lower end a bevel pinion I29 which meshes with a bevel gear IN.

The bevel gear I2I is secured to fa shaft I22 (Figs. 3 and 14), which is journaled in'a bracket I23. This bracket is 'detachably secured in 1 the base of the machine by bolts I24.

The shaft I22 drives a shaft I25 through a standard reversing mechanism which may be of any suitable construction, for instance, that described in my prior Patent No. 2,000,215 of May 7, 1935. Sufiice it to say that the shaft I25 is driven through this reversing mechanism alternately in opposite directions. It is driven in one direction by the spur gears I26 and I2! and in the opposite direction by the spur gears I28, I29

and I39. The'reversing mechanism may be controlled from the feed cam of the machine, as" in my prior Patent No. 2,000,215 and as will be referred to further hereinafter. I

The shaft I25 drives a shaft I 32 through a pair of change gears I33 and I34 which'govern the rate of roll of cradle and work spindle. The shaft I32 drives a shaft I35 through a pair of spur gears I36 and I31. The shaft I35 carries at its inner end a bevel gear I38. This bevel gear meshes with a bevel gear I49 (Figs. 4 and 14) that is keyed to a worm shaft I4I. A worm I42,

to be adjusted. After the clutch has been disconnected the gear-train driving the tools maybe adjusted by rotating the handwheel I46 (Figs. 1, 2, 3- and 14). This handwheel is secured to a shaft I41 which carries a bevel gear I48 that meshes with a bevel gear I49 which is secured to the shaft 6. The gear I 48' is moved into and out of engagement with the gear I49 by manipulation of the lever I45 (Figs. 1 and 3). This may be connected to the gear I48 in any suitable way, forming no part of the present invention.

The gear blank, which is to be cut, is secured to the work spindle I50'that' is journaled in the work head II (Figs. 1 and 2). Thelwork head I5I is adjustably mounted upon a plate- I52. for adjustment in'th directionof the axis of. the work spindle. This adjustment may be; effected by rotation of a shaft I53 which is journaled in the 'work head I5I and. which carries a spur pinion I54 that meshes with a rack' I55 which is secured to the plate. I52. Thehead .I5I is secured in any adjusted position on the plate I52 by, means of IT-bolts I51 whichiengage in elongated.

T-slots I58 that'are formed in the plate I52. The work head I5I is adjusted on the plate." I52 in accordance with the cone-distance of the gear to be cut. The'p1ate'l52 is mounted on the sliding'base' 32 for angular adjustment thereon about an axiswa: which extends at right angles to and intersects the'axes of both cradle and work spindle. The plate is secured in any adjusted positionmonythe slidingbase32 by T-bolts' I 60; whichengage in arcuatejT-slots I6I that are concentric with-the axis, x; The adjustment of the plate I52, on the sliding; base 32 isdeterminedby the pitch cone angle of-the gear to becut; M v

Thesliding bas ez32 is adjustable and reciproca: ble in the direction of the-axis of the cradlet It slides-on-parallel ways I6 3f0rmed on theupper face of the baseor frame 300i the machine.

,The work spindle I50 is'driven in time-With the cradle'rotationfor the purpose of effecting the ener i r T d ive is i msh it. 1.3

This shaft carries at. its outer. end aspur gear I (Figs. 3 and 14). This gear meshes with; aspur gear ITI that is secured to a stub-shaft I12 which are change gears governing the ratio of roll of d n qw kspi v The-shaft I carries at its-inner end one member I16 of a bevelgear differential which is enclosed'within a housing I181 The other members; of the differentialare designated at I80 and I82. The difierential abus ng H8 is formed v with sleeve-like ro ections l 11 and H9 extending from oppositesidesbf the housing. The housm isfjournaledf by means of these projectionson' anti-friction bearings I8 I and I81 in the bracket friction bearings in the 'pi'ojectio'r'f m;

Thgbevelj gear I80 is integral with the s t-art IBI which;is journal'ed 'on'janti-friction bearings is-journaled the base of themachine.

of the machine coaxial of the aki's ir o f adjust 65 i irfthe differential housirfgi Thebevel" gear I 92 is j keyed to -'a shaft-- I83 (Figs? 1; 2, 10 and '14 which witha bevel gear I89 that is secured-to the lower endof a diagonal shaft I90 which is journaled bevel gear I96 which is secured to the lower end of :a vertical shaft I91 that is'journaled' in the work head ISI.

shaft- I91 isa spur gear I98. This spur gear meshes witha spurgear I99 which is securedto a stub-shaft 209. The stub-shaft 2001s journaled in'the: work headof th machine; sp'ur gear 202 that meshes with thespur gear 203which is secured to a worm shaft 204. The worm shaft 204 has integral withit aworm 205 whichzmeshes with a; worm wheel 296 thatisfastened to the work-spindle I50. The spur gears I98.'I9'9,.202 and 203arindex change gears governing thenumberofteeth in the gear to be'cut.

Through the drive described, the work spindle is rotated in time withsthe cradle motion to impart thezgenerating roll to the work;

Whenia'-.to.oth of the gear' has been cut, the 365% Work is withdrawn ifrom' engagement with: the tools by' movement of the. sliding base 32 and when the Workiis-clearof the tools,- it is indexed. Affil'ithe iridexingr operation has been completed, the. work is fed backiinto engagement with the tools and .a" new. tooth of the blank'may' be cut. The alternate withdrawalrandfeed movements of the sliding base are controlledby. the feed cam 2I0,'(Figs; 13 and ,3). This-cam is provided with two tracks 2H and 2 I2;-oneiof which conm trols the movement of the sliding base during the rough-cutting of ,the teeth" of a-gear blank anduthe other of' which'is' em'ployed to control the .movement of uthezslidingbase during. the finish cutting: of the teeth. Two= rollers 2I3 and 2I4 respectively, are provided to engage the tracks; These rollers are carried uponthelower ends of'posts- 2I5 and 216,- respectively, which are mounted zfo'r'laxialireciprocation inthe cam lever 2I8. Racks 2 I9 'and 220, respectively; are cut.in-the' opposed faces of the 'posts' 2I'5 and 2I6.'. A spur pir'iion 222" nieshe's with the two racks; This spur pin'i'ongis integral with ashaft 223 which is journaledin-tlie lever 2I8 and is manuallyrotat'able to move'one' or the other roller 2 I3 for H4 selectivelyirito' engagement with the track 2I I or"2I2 of the cam'; When one" roller is moved-into operativeposition, the other is retracted therefrom The 1ev'e'i-"2 I81 ispi'vbtally" mounted by" means of the stud-or pin 225 111" (t-{bracket 224 that'is secured'by screws '229i in the-base of the ma: chine." Agib 226' sud -screws "221* serve to retai the lever 2I8 in place. Slidablyadjustab i'n" *emn'g atessidt" 228 formed infthe lever 21 a block i sadjus ted by 'r'nean o'fa s'ci'eW shaft" 231 which' is' 'joiirnale'd "ifi' 'tli'e l'ever-afid which threads into theblock; is" spin" 232 "iht'e'gi'a lfwith the block 230v and en this pin there is pivotally 'mEmouhted a "'secohd blbck 233; which ngage in an elongated slbt 234'for' 235 of a cylinder 236. Th mouafies m siisnsateens or g" v v 231' rs m'su m" thezbracket 52241 ;:A- istbn' 1 25s; -is"rn'ouritetlto reciprocate in the cylinder 235,

Keyedto the upper end of the It carries a' Integral with this piston is a piston rod 239 that is threaded at its projecting end into a nut 246 which is secured in a block 24I that is fastened to the sliding, base 32.

Fluid under pressure may be admitted to the opposite ends of the cylinder 236 through ducts 244 and 245, respectively. A hand operated valve 246 of any suitable construction (Fig. 3), is provided to control the direction of flow of the pressure fluid to and from the cylinder.

1 The piston 238 is shown in Fig. 13 in the position which it occupies during cutting of the teeth; of a gear blank. It is bottomed in the righthand end of the cylinder 236 and is held in such position by the head of pressure fluid admitted through the duct 244 and entrapped between the left hand end of the piston and the left hand end-wall of the cylinder. As the cam 210 rotates, then, the cylinder 236 will move-alternately to the right and left in the bracket 224, carrying withit the piston 238 and the sliding base 32. Thus the work will be moved alternately to and from cutting engagement withthe tools T and T in a limited working path determined by the shape of that cam path 2II or 2I2 which at the time may be controlling the movement of the sliding base.

The track 2 controls the movements of the sliding base 32 during rough-cutting. This camtrack will be shaped to impart alternately a. continuous depthwise feed movement of the gear blank into the cutting tools until a tooth has been cut to full depth and then to withdraw the Work from the tools for indexing. The track 2I2 is provided to control the movements'of the sliding base during finish-cutting. This camtrack is shaped to move the gear blank rapidly to full depth position and to cause it to dwell there during generation of a tooth and then to withdraw it for indexing.

At the end of the cutting operations upon gear blank, when all of the teeth have been cut, the sliding base may be moved to loading position to permit removal of the completed gear and chucking of a new gear blank, by putting the duct 245 on supply and the duct 244 on exhaust. Then the piston 238 movesto the left in the cylinder 236 carrying the sliding base outwardly beyond its normal working path to loading position. When the completed gear has been removed and a new blank chucked, the sliding base can be returned to operative position by operating the valve 246 to put the duct 244 on supply again and the duct 245 on exhaust.

The cam 2H1 is driven from the shaft I22 through a pair of bevel gears 25!! and 25I (Fig. 14). The bevel gear 25I is secured to a worm shaft 252 (Figs. 13 and 14) with which is integral a worm 253. The worm 253 meshes with. a worm wheel 255 which is keyed to the shaft 256 to which the cam 2I0 is fastened. This shaft is suitably journaled on anti-friction bearings in the bracket 224.

The index mechanism of the machine will now be described. As already stated, during cutting the difierential housing I18. is held against rotation. For indexing, the diiferentialhousingis released and is revolved to cause the bevel gear 7 I88 (Figs. 10 and 14) to revolve on the bevel gear I82 to impart to the shaft I83 and to the Work spindle an additional algebraic rotation to effect the indexing operation. 7

The differential housing is held against rotation during cutting by a lock-up dog 266 (Figs. 11 and 12) which is adaptedto engage in a 263 that is mounted in the bracket I23.

notch 26I formed in the'differential housing.- The lock-up dog 260 is integral with a lever 262;; which is pivotally mounted upon a stub-shaft The 1 locking dog 266 is held in engaging position bya coil spring 264 which seats against the back of the lever 262 and is carried in a lug 265 that posite direction from the tail portion of the lever 262 and which carries a roller 212. 'I'he'rollers 216 and 212 are adapted to engage with difierent peripheral portions of a rotary and reciprocable 1 control member 214. I

This control member'is 'slidably keyed to-a shaft 215 which is suitably journaled'inathe bracket I23. It is formed with four separate peripheral control surfaces that are successively disposed axially of the control member, one ad"- joining another. These are, in order, a peripheral cam surface 216, a truly cylindrical control surface 211, a peripheral cam surface 218and'a truly cylindrical control surface'219.

The cam surface 216 has a dwell portion 280 (Fig. 11) and a dwell portion 28I suitably con;-

nected by rises 282 and 283. The dwell portion 286 extends around nearly half of the periphery of the cam and lies at a given radialdistance from'the axis'of the shaft 215. The dwell portion 28I extends around nearly the other half of the periphery of the 'cam and lies at alesser radial distance from the axis of the shaft 215.

The cylindrical surface 211- of the control member 214 has a radius equal to the radius'of the dwell portion 28I of the cam 216. V V

The cam member 218 is constructedlike' the cam member 216, but'the major and minor diametral portions of the two cams are slightly spaced angularly relative to one another'in ac'-;

. cordance with the angular spacing of the rollers member has a radius equal to'major radius of the cams 216 and 218. I When the locking dog is in operative position,

the control member 214 is in the positiojn shown in Fig; 12 and theroller 210rides on the cylin}; drical surface 211 of the control member, which is'of minor radius. At the same time, the roller:

212 of the lever 266 rides on the cylindrical'surg." face 219 which is of major radius. Thus the levers 262 and 266 .are held in the positions" shown in Fig. 1]. andthe spring 2646s operative to hold the locking dog 260 in engagementwith" the notch 26I in the differential housing-l18..'

When the control member 214 is shifted 'axial- 1y on the shaft 215, however, the cam 216 ismoved into engagement with the roller 216 and the cam 218 ismoved into engagement with-the roller 212. The shifting ofthe control member occurs, as will be described hereinafter,. when the minor radius portion"28 I,of the ;cam 216 is 1 in registry with the point of contact between the roller 210 and the cylindricalsurface 211 and when the major radius portion of the cam 218-ls correspondingly in registrywiththe point of contact between the roller 212 and the cylindrical surface 219. Thus'the shifting'of the control member mayoccur without clash.

As the control member 214 continues to rotate, after it has been shifted as described, the roller 210 will ride up on to the portion 280 of the cam 219, which is of major radius, and the roller 212 will ride down on to the portion of the cam 218 which is of minor radius. The movement of the roller 210 up on to the portion 280 of the cam 216'will cause the lever 252 to be moved counterclockwise about the axis of the stub shaft 263, and the movement of the roller 212 down on to the portion of the cam 218, which is of minor radius, will cause a similar movement of the lever 266. Thus, the lock dog 260 will be withdrawn from operating position, releasing the differential housing I18.

The shaft 215 is driven continuously during the operation of the machine from the shaft I22 (Figs. Band 14) through a spurpinion 290 which is secured to this shaft and which meshes with a spur gear 29I (Figs. 3, 10, 11 and 14) that is journaled on a stub-shaft 292. The stub shaft 292 is journaled in the bracket I23 and carries a spur pinion 293 which meshes with a spur gear 295 that is keyed to the shaft 215.

The shifting of the control member 214 axially on the shaft 215 is effected by movement of a pivoted yoke member 291 (Figs. 11 and 12) which 7 is keyed to shaft 208 that is journaled in the bracket I23. The yoke member 291 is provided with a shoe 209 that engages in a groovev 300 formed on the control member 214 between the cam 216 and a flange I.

The shaft 298 is rocked by a lever 302 (Figs. 3 and 11) which is connected at one end to a collar 304 that is keyed to shaft 298. At its opposite end, this lever 302 is pivotally connected to an arm 305 which is keyed to one end of a shaft 306. This shaft is suitably journaled in an extension of the bracket 224 and has keyed to its opposite end an arm 301. This arm carries a roller 308. The roller 308 engages in acam track 3"] formed in the feed cam 2I0 (Fig. 13). Thus, the control member 214 is shifted in time with the feed and withdrawal operations of the ma.- chine.

The track 3II of the cam 2I0 controls the reversing mechanism of the machine through a mechanism similar to that described in my Patent No. 2,000,215 above mentioned.

When the differential housing I18 is released as above described, it is rotated to impart through the differential gears the indexing motion to the train of gears which drive the work spindle. The rotary movement of the differential housing is effected through a Geneva mechanism which will now be described.

Secured to the control member 214 as by means of screws 3I5 is a crank plate 3I6 (Figs. 10, 11, 12 and 14). This crank plate carries two angularly spaced rollers 3 I 1.

When the control member 214 i shifted 'to the right from the position shown in Fig. 12 to that shown in Fig. 10, the rollers 3I1 are moved into a position where, as the control member rotates, they will successively enter successive slots 3! of a Geneva wheel 3I9.

The Geneva wheel 3I3 has four slots extending at right angles to one another and forming a cross-shaped recess. cured to a spur gear 320. This spur gear is se-' cured to a shaft 32I that is suitably journaled in the bracket I23. It meshes with a spur pinion 322 which is inte ral with the sleeve portion H9 The Geneva wheel is se-.

of the differential housing I18. Geneva wheel 3I9 is rotated by one or other of the rollers 3I1, motion is imparted to the differential housing to'eifect an added algebraic motion of the train of gearing, which drives the work spindle, to thereby index the work spindle.

To enable any one of a group of roughed gear blanks to be quickly adjusted on the machine so that the teeth of a blank will lie in the proper relation to the cutting tools so that the'cutting tools will remove the desired amounts of stock from each of the teeth and produce a finished gear having accurately spaced teeth, the improved stock dividing mechanism of the present invention is provided. This will now be described.

As already stated, this improved stock dividing mechanism may take one of several differentembodiments. In each case, however, the stock'- dividing gauge proper is carried by a bracket 330" (Figs. 2, 15 and 16) which is mounted for lateral adjustment upon the front face of the work head I5I. The bracket 330 has a tongue adapted to engagein the elongated T-slot 332 formed in the front face of the work head and is secured in any adjusted position by the T-bolt 33I whose head engages in this slot; In the illustrated embodimerit of the invention, the median line'of the slot 332 extends radially of the axis of the Work spindle of the machine and lies in the horizontal plane containing 'the-axes of cradle and'work spindle.

The bracket 330 is formed with ears 334. Pivotally mounted upon the bracket 330 by means of a pin or shaft 331 is an arm 335. This armis keyed to the shaft 33'! and carries at its outer end a stud 336 on" which i rotatably mounted the stock dividing gauge itself.

When a roughed gear blank B has been chucked on the machine, the arm 335 is swung about its pivot to bring the stock dividing gauge into engagement with the blank. When the stock dividing operation has been completed, the arm 335is swung out of the way so as not to interfere with the cutting operations of the machine. In the illustrated embodiment of the invention, the arm is constantly urged into inoperative position by spring pressure. The shaft 331, which forms a pivot for the arm 335, has spur gear teeth 338 out around its periphery as shown in Fig. 21. A rack member 340 meshes with these teeth 338. This rack member is adapted to slide in a hole 3 3i bored in the lower ear 334 of the bracket 330. A coil spring 342, Which is interposed between therack member and a nipple 343, tends to move the'rack member constantly to the left to swing the arm 335 out of operative position. The nipple 343 is threaded into one median line of this tooth-like projection lies in' the same plane as the median line of the tongue,

which is formed on the bracket 330 and which engages in the T-slot 332. Thus, the median line of the tooth-like projection 346 will lie in the horizontal plane of the machine. Hence when the gauge is engaged in a tooth space 353 of a gear blank, the tooth 354 of the gear which is diametrically opposite that toothspace will, "as isdiagrammatically illustrated in Fig. 17, be cor:

Thus,- as the- 

